#include<bits/stdc++.h>
using namespace std;
int main() {
	cout << "change(\"b\",\"a\");" << endl;;
	cout << "change(\"c\",\"a\");" << endl;
	cout << "change(\"aaaa\",\"aa\");" << endl;
	cout << "change(\"aaa\",\"odd\");" << endl;
	cout << "change(\"aa\",\"even\");" << endl;
	cout << "change(\"a\",\"odd\");" << endl;
}



